H2O/CO2污染对煤油燃料超声速燃烧影响数值研究

在纯净空气与H₂O/ CO₂污染空气来流对比试验结果基础上,采用数值计算方法和化学动力学方法,研究了H₂O和CO₂污染组分对煤油燃料超声速燃烧的影响,获得了试验手段难以得到的燃烧室流场参数和性能数据。完成了相应的煤油燃料超声速燃烧室二维数值计算,其中匹配了进口总温、总压、马赫数、氧气摩尔分数和工作当量油气比。将数值计算结果与相应试验测量值进行了对比分析,并结合燃烧室流场数据、性能参数分析了H₂O和CO₂污染的动力学影响、以及对燃烧室性能的影响。研究表明:(1)数值计算结果与实验测量值总体上吻合,两种手段均体现了纯净空气来流时不同煤油当量油气比的燃烧室性能,并反映了一致的“污染效应”影响趋势;(2) H₂O污染、H₂O+ CO₂污染的存在降低了煤油燃料超声速燃烧室性能,体现在燃烧诱导压升、燃烧效率、流向冲量增量的下降,而且随着污染组分含量的增加,燃烧室性能下降越加显著。      

含N,S杂原子功能基螯合树脂的合成及其吸附性能

以2-巯基苯并噻唑(MBT)、2-巯基苯并咪唑(MBM)、2-氨基苯并噻唑(ABT)、氨基噻唑(AT)及苯基硫脲(PTU)与环氧酚醛树脂(F46)反应合成了五种含氮、硫杂原子功能基的螯合树脂;分别测定了各种树脂对多种金属离子的吸附性能.结果表明,树脂对不同金属离子的吸附能力不同,对Ag+的吸附符合Freundlish等温方程.     

低浓度苯胺在大孔树脂上吸附的动力学研究

测定了水相中苯胺在NKA-II和AB-8这2种大孔吸附树脂上的吸附等温线和吸附速率曲线.结果表明:极性的NKA-II对苯胺的吸附量要高于弱极性的AB-8对苯胺的吸附量,苯胺在2种吸附树脂上的相平衡关系符合Freundlich方程;苯胺在NKA-II和AB-8上的吸附受膜扩散控制.动态吸附实验和模拟结果表明:模拟透过曲线与实验透过曲线比较吻合,所建立的模型能够较好地描述苯胺在2种大孔吸附树脂填充柱上的吸附透过过程.     

Using Physiologically-Based Pharmacokinetic Modeling to Address Nonlinear Kinetics and Changes in Rodent Physiology and Metabolism Due to Aging and Adaptation in Deriving Reference Values for Propylene Glycol Methyl Ether and Propylene Glycol Methyl Ether Acetate

Reference values, including an oral reference dose (RfD) and an inhalation reference concentration (RfC), were derived for propylene glycol methyl ether (PGME), and an oral RfD was derived for its acetate (PGMEA). These values were based on transient sedation observed in F344 rats and B6C3F1 mice during a two‐year inhalation study. The dose‐response relationship for sedation was characterized using internal dose measures as predicted by a physiologically‐based pharmacokinetic (PBPK) model for PGME and its acetate. PBPK modeling was used to account for changes in rodent physiology and metabolism due to aging and adaptation, based on data collected during Weeks 1, 2, 26, 52, and 78 of a chronic inhalation study. The peak concentration of PGME in richly perfused tissues (i.e., brain) was selected as the most appropriate internal dose measure based on a consideration of the mode of action for sedation and similarities in tissue partitioning between brain and other richly perfused tissues. Internal doses (peak tissue concentrations of PGME) were designated as either no‐observed‐adverse‐effect levels (NOAELs) or lowest‐observed‐adverse‐effect levels (LOAELs) based on the presence or the absence of sedation at each time point, species, and sex in the two‐year study. Distributions of the NOAEL and LOAEL values expressed in terms of internal dose were characterized using an arithmetic mean and standard deviation, with the mean internal NOAEL serving as the basis for the reference values, which was then divided by appropriate uncertainty factors. Where data were permitting, chemical‐specific adjustment factors were derived to replace default uncertainty factor values of 10. Nonlinear kinetics, which was predicted by the model in all species at PGME concentrations exceeding 100 ppm, complicate interspecies, and low‐dose extrapolations. To address this complication, reference values were derived using two approaches that differ with respect to the order in which these extrapolations were performed: (1) default approach of interspecies extrapolation to determine the human equivalent concentration (PBPK modeling) followed by uncertainty factor application, and (2) uncertainty factor application followed by interspecies extrapolation (PBPK modeling). The resulting reference values for these two approaches are substantially different, with values from the latter approach being seven‐fold higher than those from the former approach. Such a striking difference between the two approaches reveals an underlying issue that has received little attention in the literature regarding the application of uncertainty factors and interspecies extrapolations to compounds where saturable kinetics occur in the range of the NOAEL. Until such discussions have taken place, reference values based on the former approach are recommended for risk assessments involving human exposures to PGME and PGMEA.     

铁铬系B113-2型高变催化剂上变换反应本征动力学

本文采用活塞流管式积分反应器，在1．0MPa压力下，对国产B113-2型铁铬系高温变换催化剂上变换反应本征动力学数据进行了测试．根据测定得到的数据，对幂函数动力学模型进行了模型参数估计和模型检验，得到了高度显著的动力学回归方程．从动力学方程可以得出：该高温变换催化剂的活化能比较低，因此其低温活性较好；该催化剂上H20组分对反应速率的影响比较大，推测可能是由于该催化剂中Cu组分作用的结果。C02对变换反应速率的抑制作用很大，因此为提高变换反应速率，应当设法减小C02的不利影响。H2组分对反应速率的影响均比较小．在实际应用过程中。可以忽略．     

Materials Damage by Environmental Pollutants: Data Requirements

Damage to materials of construction by atmospheric pollutants falls into three categories: corrosion, soiling, and cleaning damage. All three occur in varying degrees in the absence of pollution; to assess the impact of pollutants on materials of construction, therefore, it is necessary to determine the incremental impact attributable to the pollutants. Research to date has tended to the collection of data on effects of inadequately characterized pollutant complexes on inadequately characterized materials, followed by the imposition of arbitrary regression lines on the data, ignoring the underlying chemical kinetics. An outlook on the problem is given and approaches are suggested that will decompose the series of steps into manageable portions. This viewpoint should lead to increased understanding of the phenomena involved and thus to the ability to set rational thresholds of impact as an ingredient in the process of considering the possibility of basing ambient environmental standards on such data.     

质心参考系及其应用

主要介绍了质心参考系的定义、分析了质心参考系的运动学和动力学特征以及质心参考系在解决质点系尤其是二体问题和刚体力学问题时所带来得方便之处 .     

无烟煤及其炭化样吸附甲烷的动力学研究

用容量法测定了不同温度、不同时间甲烷在无烟煤及其炭化样上的吸附量,提出了相应的动力学公式为Q(t)=Q_0+Q_(d∞)(1-e~(-Bt))~(1/2),结果表明甲烷在无烟煤及其炭化样内的扩散活化能分别为14.3kJ/mol和26.3kJ/mol,其扩散过程则是甲烷通过微孔的流动。     

低温抗冻剂溶液玻璃化转变的临界冷却速率

生物材料的玻璃化低温保存技术已受到广泛注意。本文修正了Foutron的半经验结晶动力学模型,并用由此得到的解析表达式,构造各种浓度溶液在等温转变时的温度-时间-转变(TTT)曲线和变温转变时的连续-冷却-转变(CCT)曲线,预测实现玻璃化转变所需的最小冷却速率,以反映溶液玻璃化形成倾向的大小。结果表明,丙二醇的玻璃化形成倾向大于乙二醇和甘油。若在丙二醇溶液中加入丁二醇,可进一步提高其玻璃化形成能力。     

催化合成甲基叔丁基醚的宏观动力学研究

在特制的高压釜中,对工业条件下催化合成甲基叔丁基醚（ＭＴＢＥ）进行了宏观动力学研究．当反应液中异丁烯浓度为２．２ｍｏｌ／Ｌ,甲醇与异丁烯的摩尔比为１．２∶１,温度为５８～７４℃,催化剂为大孔“Ｓ”型酸性树脂时,其动力学方程式为－ｒＡ＝１．８６×１０７ｅｘｐ（－５６．１８／ＲＴ）ｃＡ－３．２８×１０１０ｅｘｐ（－８５．６５／ＲＴ）ｃＭ．